m=1; %mass 
Kh = 50; % horizontal spring constant
Kv = 50; % vertical spring constant

Ch = 0; %horizontal damping coeff.
Cv=0; %vertical damping coeff.


fvdb = @(vt,vy) [vy(1); (( (-Kh/m)*vy(1))+((-Ch/m)*vy(2))) ];

vopt = odeset ("RelTol", 1e-3, "AbsTol", 1e-3, "NormControl", "on", "OutputFcn", @odeplot);
ode45 (fvdb, [0 20], [2 0], vopt);

